The objective of this research is to develop efficient and rapid procedures for synthesizing polynucleotides and polynucleotide derivatives possessing any desired sequence of nucleotide units. Variations in the phosphite-triester method will be explored with syntheses conducted in solution and on silica gel supports. Attention will be given to new types of protecting groups and to anchoring groups that will enable one to release synthetic oligomeric nucleotides from the silica support as triester derivatives (which can subsequently be purified and coupled by the triester methodology to yield long chains). In addition to polymers possessing phosphodiester and phosphotriester backbones, polynucleotide derivatives with selectively designed, non-uniform backbones will be synthesized to generate substances with the recognition features of natural oligonucleotides but possessing unique properties with respect to stability, sensitivity to nucleases, and binding to complementary sequences.